©MUSource: Project Management Jülich on behalf of the BMBF.

H2Mare - Green hydrogen from the sea

For the successful market ramp-up of green hydrogen, it must be produced cost-effectively. In this context, offshore wind energy can offer a good instrument for producing inexpensive green hydrogen - especially if the hydrogen can be produced directly on site without cost-intensive infrastructure. This is precisely what is currently being investigated in the hydrogen lead project "H2Mare" project funded by the Federal Ministry of Education and Research (BMBF).

Offshore wind turbines offer great potential for the cost-effective generation of renewable energy - and thus also for the production of low-cost green hydrogen. Compared to onshore wind turbines, offshore wind turbines offer a higher average rated power and generate electricity comparatively continuously. These advantages are to be used in the H2Mare project to produce low-cost green hydrogen directly on site at sea. Due to the local generation by means of wind power, the infrastructure costs - and thus also the costs for the green hydrogen overall - can be significantly reduced.

In addition to the production of green hydrogen at sea, the production of downstream products such as green methanol or green ammonia, which can be used and transported flexibly, is also planned. To this end, the project partners want to test the use of technologies that enable carbon dioxide and nitrogen production at sea - a prerequisite for the production of green methanol and green ammonia.

In addition, future-oriented approaches such as seawater or steam electrolysis are to be tested and further advanced, as this could eliminate the need for desalination of seawater - and thus a further production step. Due to the work in a sensitive ecosystem, safety and the question of possible environmental impacts are also at the center of the research work.

Source: Project Management Jülich on behalf of the BMBF.

This is being implemented in four sub-projects:


In the "OffgridWind" project, the prerequisites are to be created for integrating an electrolyzer in a new wind turbine. This requires not only a different foundation than for "conventional" offshore plants, but also a new wind turbine design.


The H2Mare project "H2Wind" is investigating the electrolyzer to be used in the plants. The aim is that the water electrolyzer used should ultimately be able to operate very efficiently and almost self-sufficiently.

"PtX Wind"

The third sub-project "PtX-Wind" focuses on power-to-X technology and in particular on the production of green methanol and green ammonia. For this purpose,CO2 and nitrogen are to be extracted from the air on site, which are necessary for the production of methanol and ammonia. The PtX Wind project is also investigating seawater electrolysis: This should make it possible to use the water extracted from the sea directly in the electrolysis process - so that desalination would no longer be necessary.


The last H2Mare project "TransferWind" deals with overarching issues such as safety and environmental issues or infrastructure requirements at sea. In addition, the results from the other projects are to be brought together in this sub-project and an exchange between the diverse project partners is to take place.

Further information

Two research institutions from Lower Saxony are participating in the project, which is funded by the German Federal Ministry of Education and Research (BMBF). In addition to Leibniz Universität Hannover, these include the Offshore Wind Energy Foundation from Varel.

You can find more about the project here.